Thermostatic overtemperature pilot shut off



Dec, 18, i956 s. G. EsKlN THERMOSTATIC OVERTEMPERATURE PILOT SHUT OFF Filed July 20, 1954 5 Sheets-Sheet l Trix/Erzi 2F famael fs/{z'n Dec. 18, 1956 s. G. EsKlN 2,774,539

THERMOSTATIC OVERTEMPERATURE: PILOT SHUT oFF Filed July 20, 1954 3 Sheets-Sheet 2 y@ M @Mgg Dec. 18, 956 s. G. EsKlN 2,774,539

THERMOSTATIC OVERTEMPERATURE PILOT SHUT OFF' Filed July 20, 1954 3 Sheets-Sheet 5 Fi' @.4 l .92

F1 5K5 81E ai m2 87 I 4 60 Vg4 fr? z/ E 27 22:72- SAMUEL G. FSK/N UnitedStates Patent() THERMOSTATIC OVERTEMPERATURE PILOT SHUT OFF Samuel G. Eskin, Chicago, Ill., assignor to Doin Valve Company, Chicago, lil., a corporation of Iliinois Application .luiy 20, 1954, Serial No. 444,548

2 Claims. (Cl. 236-21) This invention relates to a gas burner control particularly adapted for hot water heaters and more particularly relates to a gas burner control in which the pilot is shut oif upon overtemperatures, and eects the shut ott of the main burner.

A principal object of my invention is to provide a simple and improved form of gas burner control and shut otf valve particularly adapted for hot water heaters in which the control of the gas to the hot water heater burner is attained under the control of the pilot burner.

A further obiect of my invention is to provide a novel and improved form of overtemperature gas shut oft" valve which shuts oli the ow of gas to the main burner under control of the pilot flame.

Still another object of my invention is to provide a simple and improved form of thermostatically operated gas shut ott valve so arranged as to eliminate the need ofthe overtravel spring heretofore used to prevent damage to the thermostatic element of the valve.

Still another object of my invention is to provide a novel and improved form of control valve for hot water heaters wherein the valve is operated by a thermostatic element upon fusion of a fusible thermally responsive material therein, in which the need for an overtravel spring to prevent damage to the thermostatic element and a separate return spring to return the valve to its open position is eliminated.

Still another' object of my invention is to provide a novel and improved gas shut ol Valve in whichthe thermostatic element consists in a casing containing a fusible material and closed by a metallic disk and in which the disk forms a return spring for the valve and the need for an overtravel spring to prevent damage to the thermostatic element is eliminated by accommodating the valve to ex within its valve seat.

These and other objects of my invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawings where- Figure l is a top plan view of a main burner and pilot control valve constructed in accordance with my invention;

Figure 2 is a transverse sectional view taken substantially along line lI-H of Figure l;

Figure 3 is an enlarged detail sectional view drawn to substantially the same scale as Figure 2 and showing certain details of the gas passageway through the lter for the valve;

Figure 4 is a plan view of a pilot gas shut ot valve like the valve shown in Figure 2, but showing the valve as an individual valve unit;

Figure 5 is a transverse sectional View taken substantially along line V-V of Figure 4; and

Figure 6 is an enlarged fragmentary detail view of the valve showing the valve in a flexed closed position.

In Figure l of the drawings, l have shown as gas hot water heater valve of a type adapted to be strapped to the outside ofva hot water tank andv having amain gasinlet 10 leading into a valve body 11 and having a main gas outlet 12 and a pilot gas outlet 13 to one side of the main gas outlet.

Gas enters the Valve body 11 from the inlet 10 into a chamber 15, communicating with an associated chamber 16, for supplying gas for discharge through the pilot gas outlet 13 and the main burner gas outlet 12 under the control of a plug valve 17, turnable to admit gas to a port 18 for the supply of gas through the pilot outlet 13 and to a chamber 19 of the valve for discharge through the main burner gas outlet 12 under the control of a thermostatically operated disk valve 20.

Gas lenters the chamber 16 under the control of a resilient disk valve 21 held open by thermal electric current in a well'known manner. As herein shown the valve 21 is biased to engage an annular valve seat 22 by a spring 23 and is held open by a thermal electric magnet 24, energized by a thermocouple (not shown), the tip of which may be adjacent the pilot flame.

As herein shown the valve 21 is on the end of a slidable plunger 25 having a disk 26 at its lower end, engageable with the magnet 24 and is opened under the control of a push button 27. The push button 27 is shown as being carried on the end of a depressible plunger 29 the inner end of which engages the valve 21 to open the valve and move the disk 26 into engagement with the thermal electric magnet 24 upon depression of the push button 27. The push button 27 is shown as having an interlocking ear 31 fitting within a groove 32 extending around the side of a control knob 33, for operating the plug valve 17. The groove 32 is provided with a slot (not shown) extending at right angles thereto, in the pilot position of the control knob 33, to accommodate opening of the valve 21 only when the control knob 33 is in its pilot position as is well known to those skilled in the art so need not herein be shown or described further.

The valve 2u for supplying gas through the main burner outlet 12 is shown as being biased out of engagement with an annular seat 35 by a compression spring 36 Vand as being connected with a snapacting disk 37, closing the valve 2. with a snap action, upon rise in temperature of the hot Water of the heater above the temperature for which a thermostatic element-39 is set.

The valve 2) and the snap acting mechanism for operating the same are shown and described inY an application,

Serial No. 452,142, tiled by me on August 25, 1954 and are no part of my present invention so need only herein be generally described.

As herein shown, the snap acting disk 37 is abutted by spaced fulcrum points 44B of an operating member 41 slidably guided in a guide 42 and operated by a ball 43 in said guide. The ball 43 is engageable with a cam face 44 on an operating member 45 threaded ron a stern or plunger 46, maintained in engagement with a plunger 47 of the thermostatic element 39 by a compression spring 49. The plunger 47 is shown as being extensible from a cylinder 5t) threaded within an end closure member or valve bodyl 51, secured to the lower end of the valve body 11.

The thermostatic element 39 isshown as being a so called power type of thermostatic element, such as isv shown and described in the Vernet Patent No. 2,386,181, dated January 30, 1945, although it may be of various other forms, and has been selected for its extreme power in comparison with other types of thermostatic elements, and for the relatively long range of travel of the piston or plunger 47 thereof. In ysuch types of thermostatic elements, a thermally deformable medium (not shown) is carried in a casing 53 of the element andacts against a membrane or deformable member (not shown), to' extend the'plunger or piston 47 from the cylinder 50rv and bring the cam face 44 into engagement with the ball 43 and move the ball along the pasageway 42 in a direction to snap the snap-acting disk 37 past center and close the valve against the spring 36.

The plug valve 17 also controls the supply of gas to a pilot valve 55 through the port 1S and a passageway 55 leading therefrom to a chamber 57 of the pilot valve. The pilot valve 55 has a yieldable Valve disk 6i?, which may be made of rubber, an elastomer or like resilient material which readily flexes and returns to its initial untlexed condition and which is not affected by the tion of the chemicals in the gas. The pilot valve 55 is thermostatically operated by a disk type of power thermostatic element 61, which will hereinafter be more fully explained as this specification proceeds. Gas leaves the chamber 57 through an annular seat 63 extending within said chamber and having communication with a passageway 64 communicating with a filter chamber 65 having a filter 66 therein (see Figures l and 3). From the filter chamber 65 gas leaves the valve body through the pilot gas outlet 13 through a passageway 67.

Thus when the plug valve17 is turned to its pilot position by the control knob 33 and the push butt-on 27 is depressed, pilot gas will pass through the port 18 and passageway 56 to the valve chamber 57, and will pass therefrom through the seat 63 outlet passageway 64, the filter chamber 66 and will leave the valve body through the pilot gas outlet 13.

The pilot may then be ignited either manually or under the control of an electric igniting device as the push button 27 is held down, and when it has been ignited the heat of the pilot llame will generate sutiicient thermal electric current to energize the thermal electric magnet 2d and hold the valve 21 open.

The control knob 33 may then be turned to the desired control position, dependent upon the temperature of the hot water desired, at which time the gas will pass from the chamber 16 through the plug valve 17 and out the main burner gas outlet 12 under control of the valve 2f?. The main burner may then be ignited by the ame of the pilot burner, the thermal electric current generated by the heat of the pilot ilame holding the valve 21 open and maintaining the flow of gas both through the pilot gas outlet 13 and the main burner gas outlet 12.

If, however, the temperature of the hot water within the hot water tank should exceed the temperature for which the thermostat 61 is set, the valve 55 will then close, and the pilot flame will go out. This will allow the tip of the thermocouple to cool and deenergize the magnet Z4, sufficiently to release the disk 26 and accommodate the spring 23 to close the valve 21.

The flow of gas to the main burner is thus completely under the control of the pilot flame and is shut olf upon failure of the thermostatic element 39 to act at the ternperature for which it is set and failure of the valve 20 to close.

The thermostatic element 61 is shown as being a disk type of thermostatic element in which a thin flexible metal disk 70 closes an end of the body 71 for the valve 55. As herein shown, the disk 70 abuts a shouldered portion 72 of the casing 71 of the thermostatic element and is maintained in engagement therewith by an in wardly spun annular inturned edge 73 of the casing 71, shown as being spun into engagement with a gasket or flexible washer 74 abutting the disk 70 and sealing a thermal responsive medium within the casing '71.

The inturned edge of the casing 71 may abut a gasket 74a in a recessed end of the casing 51 and is sealed in engagement therewith by a yoke 78, secured to the casing 51. The therniostatic material within the casing 71 may be of a well known form of fusible thermal responsive material containing a wax and metal powder and binder or metallic wool and wax, which expands on fusion to extend the disk 70 from the `casing 71 and effect closing of the Valve 55 upon overtemperature conditions.

As herein shown, a core 75 for the valve 55 is brazed or welded to the outer surface of the disk 70 and extends therefrom. The core 75 is shown as being drilled through its center in axial alignment with the center of the disk 7th and as being abutted at its outer surface by the resilient valve disk 6l), secured thereto as by a machine screw 76 threaded Within the core 75.

The resilient valve disk 60 extends beyond the periphery of the core 75 a substantial distance. The core 75 is also substantially smaller in diameter than the inner diameter of the seat 63 and asvthe disk 70 is extended under excessive and continued overtemperature conditions, the core 75 will press the valve disk 60 within the valve seat 63, and thus prevent damage to the thermostatic element 61. Upon reduction in temperatures and the relief of pressure the metallic disk 76 will return and withdraw the valve disk 60 from the seat 63 and open the valve,

in Figures 4, 5 and 6 I have shown a valve like the valve shown in Figure 2 except that the valve is a unit in itself rather than an integral part of an end casing member for a valve chamber. Like reference characters for like parts will thus be applied in these figures as were applied in Figure 2.

In the form of my invention shown in Figures 4, 5 and 6 i have shown a valve casing 8@ having an inlet 81 leading thereinto and an outlet 82 leading therefrom. The inlet S1 leads into an annular valve chamber 83 closed by the thermostatic element 61 abutting a sealing member or gasket 84 and held thereto in leakproof relation with respect to the end of the casing S6 by a retainer 85. rlhe retainer 35' is shown as abutting an outer shouldered portion S6 of the casing .71 of the thermostatic element 61 and as being threaded on the valve `casing Si). The valve disk 6l) is shown as abutting a seat formed by the end of an annular wall 87, extending into the valve chamber 83. The outlet S2 is shown as leading through said annular wall.

When the hot water reaches the over-temperature for which the valve is set to operate, the fusible material within the casing of the thermostatic element will extend the disk 7l? and move the valve disk 69 into engagement with the end of the annular wall S7 and block the ow of gas through the outlet S2.

Upon excessive overtemperature conditions the valve disk will tend to ex within the annular wall 87 as shown in Figure 6 like the valve shown in Figure 2, the resiliency of the valve disk 60 holding the disk 70 from over-extension and preventing damage to the thermostatic element.

The thermostatically operated or controlled pilot valve of my present invention, thus controls the supply of gas to the main burner by controlling the supply of gas to the pilot burner and shutting olf the supply of gas to the pilot burner upon over temperature conditions, in a simple manner avoiding the need of springs for the thermostatically operated pilot valve, both to return the valve upon reductions in temperature and to prevent damage to the thermostatic element upon over temperature conditions.

It will be understood that modifications and variations may be effected in the present invention without departinfg from the spirit and scope of the novel concepts thereo I claim as my invention:

l. In an over temperature pilot gas shut off valve, a valve body having an inlet for gas leading thereinto, an outlet for pilot gas leading therefrom and a spaced outlet for main burner gas also leading therefrom, a valve controlling the flow of gas into said valve body through said inlet, spring means biasing said valve to a closed position and a thermal electrically energized electromagnet holding said valve open, a valve within said body controlling the ow of gas through said burner outlet, spring means biasing said valve in an open position, a thermostatic element on the end of said valve body having operative connection with said Valve, for closing the same when the temperature sensed reaches the temperature for which the thermostatic element is set, a pilot gas valve in said valve body and having a thermostatic element extending outside of said valve body for contact with the tank of a hot water heater, and a passageway from said inlet through said pilot gas valve and from said pilot gas valve through said pilot gas outlet and including a valve seat, said thermostatic element for said pilot gas valve comprising a resilient disk, and said pilot gas valve being mounted on said disk for resilient engagement with the end said valve seat and resiliently permitting overtravel thereof.

2. In a hot water heater over-temperature gas shut 0E valve, a valve body, an inlet into said valve body, an outlet from said body for main burner gas, another outlet from said valve body for pilot gas, a valve controlling the passage of gas from said inlet into said body, spring means biasing said valve in a closed position, manually operable means for opening said valve, an electromagnet energized by thermal electric current for holding said valve open against the bias of its spring, a valve controlling the passage of gas through said main burner outlet comprising a Valve disk, snap acting means closing said valve, an extensible plunger forlactuating said snap acting means, said plunger being the plunger of a power type thermostatic element, and other thermostatically operated valve means controlling the passage of gas to said pilot outlet comprising a casing on the end of said valve charnber, enclosing the end thereof, and adapted to be associated with the wall of a hot water heater tank, a exible disk closing an end of said casing, and forming an end wall of said wall chamber, a passageway from said inlet on the downstream side of said first mentioned shut oil valve to said' pilot gas control valve, a second passage way from said pilot gas control valve to said pilot gas outlet and including an annular valve seat, and said pilot gas control valve comprising a llexible valve disk of a larger diameter than said seat and supported `on said exible disk inwardly of the margins of said valve seat and eiecting the shut oi of said iirst mentioned valve when closed by shutting off the pilot llame.

References Cited in the lile of this patent UNITED STATES PATENTS 2,013,713 Hamilton Sept. 10, 1935 2,312,479 Ray Mar. 2, 1943 2,575,081 Watkins Nov. 13, 1951 2,576,675 Drow Nov. 27, 1951 2,634,057 Hoffman Apr. 7, 1953 2,672,293 Ludlow Mar. 16, 1954 

